Freitas Tomás T, Pereira Lucas A, Reis Valter P, Fernandes Victor, Alcaraz Pedro E, Azevedo Paulo H S M, Loturco Irineu
Int J Sports Physiol Perform. 2021 Aug 1;16(8):1120–1126. doi: 10.1123/ijspp.2020-0280. Epub 2021 Mar 10.
To investigate the effects of a match-congested period on straight and curve sprint performance, change of direction (COD) speed and deficit, vertical jumping ability, and half-squat (HS) mean propulsive power (MPP) output in young soccer players.
A total of 15 under-20 elite male soccer players participated in 14 matches over 8 weeks. The following assessments were performed before and after the congested fixture period: squat and countermovement jumps, 17-m linear sprint, curve sprint test for the "good" (CSGS) and "weak" (CSWS) sides, modified 17-m Zigzag test, and HS MPP. Magnitude-based inferences and a paired t test were used to analyze pre-post changes in the assessed variables.
Very likely (P < .05) decreases were noticed in 17-m sprint velocity (effect size [ES] [90% confidence limit; CL], -0.56 [-0.32 to -0.81]) and CSGS (ES [90% CL], -0.72 [-0.40 to 1.03]) after the 8-week period. A possible but nonsignificant impairment was revealed in CSWS (ES [90% CL], -0.18 [0.03 to -0.39]), and countermovement jump (ES [90% CL], -0.21 [-0.54 to 0.12]). Zigzag velocity (ES [90% CL], -2.90 [-2.45 to -3.36]) and COD deficit (ES [90% CL], 0.86 [0.52 to 1.20]) were almost certainly and significantly (P < .05) reduced and increased, respectively, after the match-congested period. An almost certain and significant (P < .05) reduction was found in HS MPP (ES [90% CL], -1.18 [-0.76 to -1.61]).
Straight and curve sprint velocity, COD speed and deficit, and HS MPP were impaired after the match-congested period. Vertical jump height was possibly decreased. Seasonal phases comprising high volumes of soccer-specific training and competition seem to be detrimental to speed-power qualities in under-20 elite soccer players.
探讨比赛密集期对年轻足球运动员直线和曲线冲刺成绩、变向（COD）速度和差值、垂直跳跃能力以及半蹲（HS）平均推进功率（MPP）输出的影响。
共有15名20岁以下的精英男足球运动员在8周内参加了14场比赛。在密集赛程期前后进行了以下评估：深蹲和反向移动跳跃、17米直线冲刺、“优势”（CSGS）和“劣势”（CSWS）侧的曲线冲刺测试、改良的17米之字形测试以及HS MPP。基于量级的推断和配对t检验用于分析评估变量的前后变化。
8周后，17米冲刺速度（效应量[ES][90%置信区间；CL]，-0.56[-0.32至-0.81]）和CSGS（ES[90%CL]，-0.72[-0.40至1.03]）极有可能（P<.05）下降。CSWS（ES[90%CL]，-0.18[0.03至-0.39]）和反向移动跳跃（ES[90%CL]，-0.21[-0.54至0.12]）显示出可能但不显著的损伤。在比赛密集期后，之字形速度（ES[90%CL]，-2.90[-2.45至-3.36]）和COD差值（ES[90%CL]，0.86[0.52至1.20]）几乎肯定且显著（P<.05）分别降低和增加。HS MPP几乎肯定且显著（P<.05）降低（ES[90%CL]，-1.
